for channel. 2 is given by. T2(k kdX. "X = = 11.3356. #m. T2(X) dk. The half-maximum points for the response function occur at k 1= 10.50/Jm ! t .rid i ! k2 = 12.12.
Technical Memorandum 80258
IiEAT CAPACITY MAPPING RADIOMETER (HCM_ LGORITHM, DATA PROCESSING CALIBRATION, AND FLIGHT PERFORMANCE EVALUATION J. R. Bohse, M. Bewtra, and W. L. Barnes
,
APRIL 1979
_t T
NationalAeronauticsand SpaceAdministration Goddard Space FIIgM Cemer Greenbelt,Maryland20771
,. !
TM 80253
HEAT CAPACITY
MAPPING
DATA PROCESSING _
*
AND FLIGHT
:
:
!"
PERFORMANCE
(HCMR)
CALIBRATION, EVALUATION
Bohse
and Applied Sciences
Computer
..
ALGORITHM,
J.R. Systems
RADIOMETER
(
Corporation
M. Bewtra Sciences Corporation
W.L. Barnes Cmddard Space Flight
'
Center
J
t
t a e
April 1979
•
,
! I
.
i 'i i I
National Aeronautics and Space Administration Goddard Space Flight Center Greenbelt, Maryland
HEAT CAPACITY
MAPPING
DATA PROCESSING AND FLIGHT
RADIOMETER
ALGORITHM,
CALIBRATION,
PERFORMANCE
EVALUATION
J. R. Bohse* and Applied Sciences
Systems
(HCMR)
Corporation
M. Bewtra Sciences Corporation
Computer
W. L. Barnes Goddard
Space Flight
Center
!
ABSTRACT
This document presents calibration
the rationale
and correction
Instrument-level
and procedures
of Heat Capacity Map-ping Mission
testing
and calibration
(HCMR) were performed
by the sensor
The principal
results
characteristics
are included
and calibration
algo-'ithm for post-launch Integrated
used in the radiometric
spacecraft-level
contractor
data obtained
sensor
ITT Aerospace/Optical
•
of the validation
of the instrument radiometric
during ITT acceptance
calibration
indicated
are presented
Anomalies
a loss in sensor
by an outgassing
procedure
tests,
an
was developed,
and the data system
results.
Division.
From the instrumental
was performed
Center (GSFC) approximately 2 months before hunch. opportunity to validate the data calibration algorithm. results
t
of the Heat Capacity Mapping Radiometer
in this document.
processing
I
(HCMM) data.
sensitivity performed
In addition,
after launch are examined
and their consequences with time.
was turned on. It is planned to repeat this procedure
I
_
!
i
_: I
:
i !
:
*'i !
:
!
with respect
are discussed.
to the
Flight data
65 days after the infrared periodically.
1
the performances
The loss was shown to be recoverable
approximately
_
at Goddard Space Flight
This calibration provided an Instrumental parameters and
in this document.
!
channel
!
i I
*Thhworkperformedwhileaffiliatedwith ComputerSciencesCorporation.
lii PRECEDING PAGE
BLANK
NOT
FILMED
i
Results taken '_
of comparisons at White
approximately alternative
Sands,
solution,
the
The values
satellite
New Mexico,
6 degrees
measurements. the surface
between
Kelvin
obtained
higher
calibrated
validity
are
by various
also than
data
of this
measurements
were
change
and surface
presented. satellite offset
Surface
IR measurements
measurements. to ensure
will be verified
experimenters
measurements
and
Due to a lack
agreement by comparing
from
are
additional
with
surface
the data White
of
with
q
Sands
data.
|
FOREWORD The algorithm document
and software
were performed
24350 Task 403. .
Portions
development
and testing
by two of the authors of the document
and analysis
(JB and MB) under
described
in this
contract
are taken from the final report
NAS5of this work
(CSC/TM-79/6016). Instrumentalparameters and calibration datawere compiledfrom theHCMR
It
Engineering
Report
(Contract
NAS5-20621)
of the ITT Aerospace/Optical
Final
Division,
Fort Wayne, Indiana. The authors wish to acknowledge Capacity
Mapping Mission
Mapping Radiometer
the valuable
Project
Technical
Scientist
support of Dr. J. C. Price, and Mr. H. F. Shaw,
Heat
Heat Capacity
Officer.
V o
TABLE OF CONTENTS Page Section 1 - Introduction 1.1 1. 2 1.3
D
q
........................
1
Background ........................ HCMR ........................... Document Over_-lew .....................
1 1 2
Section 2 - Instrumental Parameters and Calibration ITT Acceptance Tests .................... 2.1 2.2 2. 3 2.4
Telemetry and Electronic Performance Visible Channel Data .................... Infrared Channel Data .................... Optical Registration Data ..................
Section 3 - Data Processing Algorithm and Correction ...................... 3. 3. 3. 3. 3.
1 2 3 4 5
3. 5. 1 3. 5. 2 3. 5. 3 3. 6 3. 6.1 3. 6.2
.
............
for Radiometric
12 12 17 29
Calibration 31 .
Count-To-Voltage Conversion ................ Channel 1 Data Calibration ................ Channel 2 Data Cslibration ................. Master Output Tables ................... Primary Tables .................... Secondary Tables ...................... Spacecraft
Calibration
Near-Real-Time Data Pxocessing Infrared Channel • *, • • • • • Visible Channel ...................
System
4. 4 4 4. 4.
Summary of Results .................... Infrared Channel Visible Channel Testing of Preflight Calibration Constants Conclusions ........................
•
•
•
PAGE
BLANK
N(.
......
59
........... •
•
•
•
...........
vt
PRECEDING
31 32 36 37 38 40 44 44 48 50 54
Thermal-Vacuum
4. 1 4 • 1• 1 4. 1. 2 2 2 1 2 2 3 4
12
Functional Description of HCMM Primary Data Processing Basis of HCMR Radiometric Correction Algorithm ...... Master Output Table Concept ................ Housekeeping Data Extraction Scan Data Calibration ....................
Section 4 - Integrated •
Data From
FILMED"
•
,
•
•
•
•
•
59 60 63 65 65 73 73 89
_: i i ! }
I i :, !
! '
+2 TABLE
OF CONTENTS
(Cont'd) Page
"
Section 5 - Flight
,
Performance
Evaluation
...............
5. 1 5. 2 5.3 5. 3.1 5. 3. 2 5. 4 5.4.1 5. 4.2
Processing System for Noise and Performance Analysis Summary of Results ..................... Master Data Processor Simulation Software .......... Results of Noise Analysis for Calibrated Data ......... Ground Truth Comparisons ................. Conclusions ........................ Cooler Temperature Regulation ............... Postlaunch Sensor Sensitivi W .................
5.4. 3 5. 4. 4 5, 4, 5
Postlaunch Value of Thermal Gradient ATBB ........ Losses in Optical Transmission ............... Compensation for Changes in Sensor Performance
_'
References
_.
Appendix
Program
......................... A
87 ....
......
87 88 93 93 99 101 101 102 103 103 105 106
..........................
107
Program Program Program
CCTANL MDPSIM CORECT
..................... .................... .....................
Listings
..........................
108 115 123 128
I
vii
h !
,,w
|1
,|
LIST OF ILLUSTRATIONS Figure
Page
_ : i
•
1-1 1-2 1-3 1-4 1-5 2-1 2-2 2-3
HCMR Pertinent Features (Front View) ............ HCMR Pertinent Features (Back View) ............ HCMR Functional Block Diagram ............... HCMR Scan Sequence .................... HCMR Analog Data Formant ................. HCMR Detector Response for Chanp-I 1 ............ Near-Infrared Calibration .................. Spectral Response of HCMR HgCdTe (Serial Number
at 115 degrees K .................... Transmission Characteristics of Germanium Band Pass Filter ..........................
22
2-4
2-5
HCMR Spectral
24
2-6
Family Curves....................... Obtained by Plotting Calibration Values of Tableof 2-7 Average Difference Between Blackbody Temperature From Signal Line and Blackbody Temperature Read From Signal . HCMR Data Format .................... HCMR Radiometric Calibration and Correction ........ Channel 1 CalL.ration (General) ............ Channel 2 Calibration (General) .............. Channel 2 Calibration (Internal Blackbody) ......... Sample Report ................ ....... Actualand FittedLoss InSensitivity Prior toUndervoltage Condition......................... Actual and Fitted Loss inSensitivity After Recovery From Undervoltage Condition .................. Subprograms for CCTANL ............... Flowchart for CCTANL ........... ...... Subprograms for MDPSIM .................. Flowchart for MDPSIM ................. Subprograms for CORECT ................ Flowchart for CORECT ..................
._
L
2-7 3-1 3-2 3-3 3-4 3-5 5-1 5-2 5-3
•
A1 A2 A3 A4 A5 A6
Response,
Infrared
viii
Channel
5 6 7 8 9 18 20 T-l)
..........
23
27 28 39 41 45 46 49 89 94 96 109 110 116 117 124 125
_
LIST OF TABLES Table
b
1-1 1-2 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 3-I 3-2 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10 4-11 4-12
•
4-13 4-14 4-15 4-16 4-17 4-18 4-19
Page HCMR System Characteristics................ HCMR Telemetry List ................... Analog Telemetry Data ................... HCMR CalibrationSteps ................. Measured Values ofNEAT and Signal-to-NolseRatio ...... Measured SpectralData ................... Near-InfraredCalibration.................. HCMR SpectralResponse Parameters, InfrareOChannel .... InfraredAnalog CalibrationData ............. HCMR IFOV and RegistrationData .............. PreflightConstantsforHCMM RadlometrieCalibration..... Nominal VoltsforInputand OutputCalibrationSteps ...... Constantsfor ProcessingSpacecraftCalibrationData ...... Coefficients forConvertingInfraredVideo Outputto Temperature ....................... Com.parlsonof Temperatures Using ITT Calibrationand SpacecraftCalibration- Hot Cycle ............. Comparison of Temperatures Using ITT Calibration and Spacecraft Calibration - Ambient Cycle ........... Comparison of Temperatures Using ITT Calibration and Spacecraft Calibration - Cold Cycle ............ Spacecraft CaLibration Data (Infrared) - Hot Cycle ....... Spacecraft Calibration Data (Infrared) - Ambient Cycle ..... Spacecraft Calibration Data (Infrared) - Cold Cycle ...... Typical rms Noise Values for Spacecraft Test (Infrared) . . . Comparison of Spacecraft Calibration Data With ITT Data for Infrared Input Calibration Steps - Hot Cycle. ......... Comparison of Spacecraft Calibration Data With ITT Data for Infrared Input Calibration Steps - Ambient Cycle ....... Comparison of Spacecraft Calibration Data With ITT Data for Infrared Input Calibration Steps - Cold Cycle . . . . . . . . Visible Calibration Prior to Spacecraft Test .......... Visible Calibration After Spacec,ttft Test ........... Typical rms Noise Values for Visible Channel ......... Comparison of Spacecraft Data With ITT Data for Visible Input Calibration Steps (January 30, 1978) .......... Comparison ofSpacecraft Data With ITT Data for Visible Input Calibration Steps (March 1, 1978) ........... Comparison of Cal/bmted Target Temperatures and Measured Target Temperatures - Hot Cycle ......... Comparison of Calibrated Target Temperatures and Measured Target Temperatures - Ambient Cycle .......
3 10 13 14 15 16 19 21 25 30 35 43 61 64 66 67 68 69 70 71 72 74 75
_.
76 77 78 79
_I
80
'.
81 83
1 i
84 r
ix
PRECEDING PAGE BLANK NOT F/'L_'yD
.,j
SECTION
1 - INTRODUCTION
1.1 BACKGROUND .
The Heat CapacityMapping Mission CHCMM)
isthefirstof a seriesof scheduled
missions to supporttheApplicationsExplorer Mission (AEM) projectand has •
been designated ping Radiometer
AEM-A.
The AEM-A
(I-ICMR) instrument
from the Earth in two spectral tinct modules:
_"
designed
bands.
(1) the base module,
and data handling equipment instrument
module,
structure,
and thermal
spacecraft
to monitor
The spacecraft which contains
(except for science
which contains
carries
a Heat Capacity infrared
radiation
is composed
of two dis-
the attitude control,
sensor
Map-
equipment),
the HCMR and its supporting
power,
and (2) the
electronics,
control.
In April 1978, the AEM-A spacecraft
was launched
and injected
into a neart
Earth,
600-kilometer,
ascending
Sun-synchronous
node and a 97.79-degree
of the spacecraft Science
circular,
inclination.
is 1 year from launch.
data, consisting
orbit with a nominal 2 p.m. The expected
scientific
HCMM is a real-time-only
of data from two analog radiometer
lifetime
mission.
channels,
t
are e
subcarrier-multiplexed
on a real-time
ing attitude and some radiometer pulse code modulation link.
calibration
data,
(PCM) and transmitted
These PCM data are also transmitted
Subcarrier _,
S-band link.
assignmente
Housekeeping are formatted
data,
into biphase
on a very-high-frequency on a subcarrier
Includ-
(VHF)
of the S-band link.
;
for the link are as follows:
"
•
800 ldlohertz:
HCMR thermal
'
•
480 kilohertz:
HCMR visible
•
70 kilohertz:
channel
i L
e
1.2
spacecraft
channel
i
PCM
HCMR h i
The HCMR is a two-obanmfl coMaln the speotral i_terva_
_annlng/imaging
radiometer.
Tim two channels
of O.58 to L 1 microns and 10. 5 to 12.5 micronm
;
! -
4
' m
,
u
t!
and share a common collecting
optical
view of 0.83 -+0.17 milliradian. teristics.
Figures
system
having an instantaneous
Table 1-1 describes
1-1 and 1-2 show the locations
HCMR system
of the pertinent
field of charac-
features
of
the HCMR. Figure
1-3 is a simplified
electronics
transmits
with the spacecraft signals 4
block diagram
to the spacecraft
two channels
The HCMR
of video data synchronized
clock and the rotation of the HCMR scan mirror.
to the HCMR are the spacecraft
clock signals
of the HCMR electronics.
of 70 kilohertz,
+28.0-volts-direct-current
14 kilohertz,
and 560 hertz
The input (VDC) bus;
two-phase;
and space-
!
craft commands
to the HCMR to implement
_
TI..9 HCMR electronics
'
generation,
provides
power conversion,
digital and analog telemetry
nal amplification
the available
modes
of operation.
timing and control,
for verification
of operation,
signal and sig-
for required operation.
The basic blocks of the HCMB electronics
are as follows:
1.
Infrared
data amplifiers
2.
Visible
3.
Power converter
4. 5.
Vol.tage regulators Timing and control circuits
6.
Calibration
7.
Analog telemetry
8.
Command and digital telvmet_-T city, tits
data amplifiers
signal generation
i ' circuits
_
circuits
!
• The HCMR scan sequence, the corresponding
times
i
angular representations are provided in Figures
for various 1-4 and I-5.
quantttites,
: i
and
Table I-2 pro-
' _
i
v/des digital andanalogtelemetry listings,
l
1. $ DOCUMENT
i!
I
OVERVIEW
i
Section 2 of this document presonts data from ITT Aerospace
acceptanoe
instrumental tests.
'
parameters
Only those results
and calibration that pertain to
J
t
t
i ,t
Table
'
l-l.
HCMR _ystem
Characteristics
PARAMETER
(1 of 2)
VALUE/DESCRIPTION DESIGN PARAMETERS
"_'
"
WAVELENGTH
BAND AT HALF-POWER POINTS
0.55 TO 1.1 MICRONS, 10.5 TO 12.5 MICRONS
FIELD OF VIEW
0.83 MILLIRAOIAN
GROUND RESOLUTION 600 KILOMETERS)
_._ t
hi
(SUBSATE LLITE POINT AT 0.5 KILOMETER
OPTICAL SPEED
fl0.82
COLLECTING
8.0 INCHES
APERTURE DIAMETER
DETECTOR TYPE
HgCdTe-SILICON
OPERATING
115 DEGREES KELVIN
TEMPERATURE
SCAN RATE INFORMATION
14.0 REVOLUTIONS BANDWIDTH
(K) (AMBIENT)
PER SECOND
53.0 KILOHERTZ
DYNAMIC RANGE CHANNEL 2 CHANNEL 1
260 TO 340 DEGREES K O. TO 100-PERCENT ALBEDO PERFORMANCE
NOISE EQUIVALENT TEMPERATURE (NETD) (CHANNEL 2) SIGNAL-TO-NOISE
CHARACTERISTICS
l
DIFFERENCE 0.3 DEGREE K AT 280 DEGREES K
RATIO (CHANNEL 1)
1
10 AT 1.0-PERCENT ALBEDO t
l
PHYSICAL CHARACTERISTICS
:
t
!
I
i
•
WEIGHT
53.8 POUNDS
SIZE
22 BY 12 BY 17 INCHES
POWER (HIGH-LOW)
_1.0 WATTS-2'_ .0 WATTS
INSTANTANEOUS
FIELD OF VIEW
OPTICAL PARAMETERS $OUARE, 0.113MILLIRADIAN
i
"_'_ ON AN EDGE
TELESCOPE
e
i
TYPE CLEAR APERTURE DIAMETER
AFOCAL DALL-KIRKAM B.00 INCHEB
:
F-NUMBER (PRIMARY) EXIT BEAM DIAM,_.TER
0.92 1.00 INCH
i
MIRROR $uBIrrRATIE MATERIAL PRIMARY-BECONOARY $PACER MATERIAL COATING
CERVIT INVAR ALUMINIZED COATING
_,
IYITEM OPTICAL PARAMETERS, CHANNEL
WITH KANIGEN PROCIBIING _
NEAR-INFRARED
RELAY EFFECTIVE IYrrEM
I
FOCAL LENGTH
: _" i
AIR$PACE TRIPLET; FOCAL LENGTH _.0 MILLIMrrER8
32.MILLIMETER
•.-
Table
1-1.
HCMI_ System
Characteristics
(2 of 2)
|
!
PARAMETER
VALUE/DESCRIPTION
I m
OPTICAL PARAMETERS
F.,NUMBERm FIELD STOP EDGE WIDTH DIAMETER OF BLUR SPOT, ON AXIS DIAMETER OF BLUR SPOT, FIELD CORNER MODULAR Trl ,NSFER FUNCTION (ON AXIS) AT THREE LINE PAIRS PER MILLIMETER MODULAR TRANSFER FUNCTION (FIELO) CORNER) AT THREE LINE PAIRS PER MILLIMETER FOCUS ADJUSTMENT CLEAR APERTURE
T
-:
SYSTEM OPTICAL PARAMETERS, CHANNEL
(CONT'D)
1.26 0.0084 INCH 0.0016 INCH b 0.0022 INCH b 99.3 PERCENT
99.2 PERCENT t0.0326 INCH 6.56 INCHES ¢
FAR INFRARED
RELAY EFFECTIVE SYSTEM FOCAL LENGTH FIELD STOP EDGE WIDTH
SINGLE GERMANIUM FOCUS LENS WITH GERMANIL_I APLANAT LENS; 23.776-MILLIMETE" FOCAL LENGTH Ii0.2 MILLIMETERS 0.0(02 INCH
F-NUMUR
0.8._
, {
DIAMETER OF ILUR SPOT, ON AXll DIAMEIER OF BLUR SPOT, FIELD CORNER MODULAR TRANSFER ;:UNCTION (ON AXIS) AT 3.8 LINE PAIRS PER MILLIMETER
0.0012 INCH d 0.0042 IP!CHd
i ; t _
MODULAR FUNCTION (FIELD CORNER)TRANSFER AT 3.8 LINE PAIRS PER MILLIMETER FOCUS ADJUgTMENT (AIR MADE BEIWEEN FOCUI LENS AND APLANAT) CLEAR APERATURE
IF-NUMIER
DEFINED
AS EFFECTIVE
;
"
99.0 PERCENT It 118.EPERCENT t0.141 INCH S INCHES
FOCAL LENGTH DIVIDED
i
BY CLEAR APERTURE DIAMETER
bFOR SPECTRAL BAND FROM 0.80 TO 1.10 MICROMETER8 AND 100.PERCENT ENrRGY CLIMITED IY SIZE OF RELAY LENS; COULD NOT BE CHANGED WITHOUT EXTENSIVk REDESIGN
k
dFOR tO0.PEIPtCENT INERGY
! |
J
i"
.:
"
';
_+, t
,_i-ill__,til
.....
r'
_
_lt..m,
....
__
L
I,' J
oc:'_,[3 )F pOORQUgLI3"_ C
.._uo _ "_,_o
!
4
I -i _-ai 6
"i'
_JRIGINAL PA_E
iS
,F POOR QUALITY
K J
0
=
NML
1
I
C E F
=
:
REFERENCE LETTER
ANGLE (DEGREES)
TIME (ms)
A B C D E F G H I J K L
0 3.6 21.6 34.2 42.9 109 175.1 189 239.4 270.4 278.3 304.2
0 0.714 4.28 6.79 8.51 21.63 34.74 37.5 47.5 53.66 55.22 60.36
M
311.4
61.78
N O P
318.6 325.8 333.0
63.21 64.64 66.07
BEGIN SYNC PULSE #I END SYNC PULSE #1 B;'GIN INPUT CALIBRATION END INPUT CALIBRATION BEGIN EARTH SCAN NADIR END EARTH SCAN BEGIN OUTPUT CALIBRATION END OUTPUT CALIBRATION BEGIN INTERNAL TARGET VIEW COMPLETE INTERNAL TARGET VIEW BEGIN INTERNAL TARGET TEMPERATURE TELEMETRY ENO INTERNAL TARGET TEMPERATURE TELEMETRY BEGIN SYNC PULSE#2 END SYNC PULSE #2 BEGIN PRECURSORBURST
O
361.0
69.64
END PRECURSORBURST
Figure
1-4.
EVENT
HCMR
8
Scan Sequence
I j!
', _-
',
.0
.
UVOSHJ.UV|il9|ll sw zg'8 sw6L'9 smfR'IP
•
dWV13gOVdSstuZII6'E o .,_---|# |rind "3NAS
az
i
u
i i
I
9
Table 1-2.
HCMR Telemetry
List
f FUNCTION
I I
ANALOG +15-VOLT +5-VOLT _
TELEMETRY
MONITOR
1
MONITOR
1
-15-VOLT MONITOR TELEMETRY POWER
1 1
MOTOR DRIVE CURRENT
1
CONE COVER POSITION
_
(PER SECOND) SAMPLE RATE
1
ELECTRONICS TEMPE RATU R E
1/8
BASEPLATE TEMPERATURE
1/8
CONE TEMPERATURE
1/8
PATCH TEMPERATURE
1
BLACKBODY TEMPERATURE
1
1
BLACKBODY TEMPERATURE
2
1
PURGE PRESSURE
1
CONE WALL HOUSING TEMPERATURE
1/8
PATCH POWER
1
ELECTRONICS CURRENT
1
OF FSET VOLTAGE
I
MOMENTUM COMPENSATOR SPEED
1
SCAN MOTOR SPEED MOTOR HOUSING TEMPERATURE
DIGITAL
:
!
1 1/8
TELEMETRY
m
-I
'
,j !
MOTOR STATUS
1
ELECTRONICS STATUS
1
MOTOR POWER STATUS
1
PATCH HEATER STATUS
1
CONE HEATER STATUS 1
1
PURGE VALVE STATUS
1
CONE COVER STATUS 2
1
•
+i
the radiometric tion 3 contains describes
of the instrument metric
HCMM primary
results.
ance of the sensor
the algorithm in Section 4.
and the data system Anomalies
(GSFC).
Section
scheme and correction
spacecraft
earlier.
5 examines
after launch with respect
Results
Sec-
algo-
calibration
Data taken during this call-
developed
and their consequences
are discussed.
processing
from the integrated
at Goddard Space Flight Center
are also included
of HCMM data are included.
of the HCMM radiometric
the results
bration were used to validate validation
_-
a review of the entire
Section 4 presents
performed
_
and correction
the basis and development
rithm.
,
calibration
discovered
of comparisons
Results
of this
the performance to the radioin the perfmun-
between
satellite
Lp
and ground measurements !
taken at White Sands, New Mexico,
sented.
11
are also pre-
SECTION 2 - INSTRUMENTAL PARAMETERS DATA FROM ITT ACCEPTANCE
The final performance
characteristics
Aerospace,
the instrument
ITT facility
as part of the acceptance
plemental
information
(References
of the HCMR were determined
manufacturer,
1 and 2).
Because
the algorithm
sults and calibrations
marily ometric
source for following
with the radiometric evaluation
TELEMETRY
Table 2-1 lists
by ITT are reproduced sections.
Because
calibration,
documents
AND ELECTRONIC
measured
temperature
covering
Table 2-2 records
values
of these
steps for both channels
parameters
parameters
voltages
as functions
of baseplate
the measured
in the infrared
channel and the signal-to-noise
2.2
ba_plate
pertinent
to a radi-
information
may be
associated
as functions Celsius
with the HCMR of baseplate
(C) to 40 degrees
C.
for the input and output calibration
Table 2-3 lists
selected
values
deals _Jri-
1 and 2).
the test range of 5 degrees
the measured
as a
PERFORMANCE
all of the analog telemetry
and presents
many of the re-
this document
Additional
the it is
in this section
only those results
(References
by ITT
of the instrument, this,
at the
and sup-
for interpreting
To facilitate
of the data are presented.
found in the original 2.1
developed
by ITT
conducted
in two reports
characteristics
data frequently.
presented
of tests
The test results
on the HCMR were presented
to refer to these
reference
in a series
procedures.
data was a function of the particular necessary
AND CALIBRATION TESTS
temperature.
of the noise equivalent
temperature
ratio in the visible
(NEAT)
channel at
temperatures.
V_SIBLE CHANNEL DATA
Table 2-4 lists the measured
spectral
of the visible/near-infrared channel.
data for the various
optical components
3
V _
4
Table
2-2.
STEP NUMBER
HCMR Calibration
BASEPLATE TEMPERATURE +5
+ 10
+ 15
+20
NEAR-INFRARED
*
-0.002
Steps
(DEGREES C)
+25
+30
+35
+40
INPUT (VOLTS)
1
-
--0.002
0.001
0.007
0.003
2
-
1.003
1.004
1.006
0.997
1.001
1.006
1.002
3
-
1 982
1.982
1.986
1.976
1.979
1.986
1.980
4
-
2.989
2.990
2.989
2.980
2.983
2.939
2.984
5
-
3.957
3.968
3.967
3.958
3.961
3.967
3.964
8
-
4.983
4.987
4.983
4.974
4.977
4.984
4.977
7
-
5.957
5.964
5.962
5.952
5.953
5.962
ill
0.002
-0.002
m
5.953 iB
NEAR-INFRARED
OUTPUT (VOLTS)
i
1
--
0.011
0.002
0.006
0.005
0.002
0.008
0.006
2
-
0.978
0.969
0.969
0.970
0.969
0.969
0.969
3
--
1.976
1.967
1.972
1.969
1.966
1.970
1.9687
4
-
2.951
2.947
2.948
2.947
2.945
2.947
2.945
5
-
3.958
3.954
3.964
3.956
3.952
3.952
3.954
6
-
4.934
4.929
4.928
4.929
4.926
4.929
4.927
7
-
5.928
5.926
5.924
5.922
5.923
5.925
6.923
ill
INFRARED i
i
INPUT (VOLTS)
I
i
•
i
1
0.102
0.104
0.102
0.104
0.102
0.102
0.101
0.098
2
1.062
1.062
1.060
1.056
1.058
1.067
1.060
1.053
3
1.987
1.991
1.988
1.986
1.991
1.990
1.991
1.988
4
2.945
2.945
2.942
2.940
2.943
2.944
2.946
2.942
5
3.887
3.883
3.874
3.877
3.875
3.875
3.875
$Jl73
6
4.855
4.852
4.848
4.842
4.947
4.849
4.852
4.843
7
5.789
5.783
5.'778
6.778
5.780
5.783
5.783
5.777
"_
inl
INFRARED
Am
OUTPUT (VOLTS)
I
0.012
0.008
0.007
0.010
0.Cli
0.008
0.007
0.010
2
0.978
0.970
0.966
O.HD
OJIBB
O.9m
0.966
0.998
3
1.966
1.984
1.864
1.962
1.982
1.962
1.961
1.9(10
4
2.940
2.938
2.936
2.935
2.938
2.836
2.036
2.936
5
3.949
3.947
3.947
3.944
3.944
3.944
3.942
3.942
6
4.926
4.922
4.919
4.921
4.919
4.917
4.919
4.914
7
6.921
5.915
5.916
6.914
6.917
6.912
6.913
6.910
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temperature
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Figure
calibration
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2-2 presents
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INFRARED
CHANNEL DATA
Table 2-6 lists the measured in the spectral Figure
spectral
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2-3 is a plot of the relative Figure
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spectral
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K.
the germanium
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of the HgCdTe detector
2-4 is a plot of the transmission
response
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channel.
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of the total relative
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of the infrared
Table 2-7 lists the calibration
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temperatures
temperatures,
characteristics Figure
of
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curves
obtained by plotting the calibration
Figure
2-7 is a plot of the difference
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2-6 shows the family of
values of Table 2-7.
i
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in channel 2 and the temperature
blackbody located in the backscan ATBB, location
Figure
position
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This quantity,
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Near-Infrared
Calibration
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NUMBER OF LAMPS,ON a
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NEAR-INFRARED OUTPUT (VOLTS)
8
102.3
6.0890
7
89.3
5.3186
76.2
4.5534
5
63.6
3.7870
4
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3.0438
3
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2.2546
2
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